Quality improvement in 'vignoles' through clonal selection

Vignoles? is a valuable component of the wine grape cultivar portfolio in the eastern United States. Because it is relatively winter hardy, ?Vignoles? is grown in such diverse locations as New York, Missouri, Indiana, Ohio, Pennsylvania, Illinois, Nebraska and Michigan. However, Vignoles has tight clusters prone to bunch rot, and losses up to one third of the crop are possible. Despite consumer demand for Vignoles, its production is limited by bunch rot susceptibility associated with compact cluster architecture. Our goal is to select a loose-clustered clone of ?Vignoles? that will contribute to an integrated approach to disease control. Following gamma radiation, irradiated buds and non-irradiated controls were bench grafted onto 3309C rootstock. A total of 2,336 vines, including 30 non-mutagenized ?Vignoles? control vines, were planted in 2007 (500 vines) and in 2008 (1,839 vines). The experimental vineyard is located at the Cornell Lake Erie Research and Extension Laboratory (Portland, New York) in the Lake Erie shore grape and wine production region. Vines were cultivated in grow tubes and drip irrigated to promote rapid vine establishment and growth. The vines were trained to a bilateral cordon, spur pruned, and cultivated following standard practices for hybrid wine grape cultivars in western New York, including fertilization and weed, pest, and disease management. Many clones planted in 2007 fruited in 2008, but fruit was dropped to encourage vegetative establishment. The generation of new clones and the establishment of the vineyard are complete. The second stage of the project is evaluation of cluster looseness and bunch rot susceptibility. A pyramidal selection approach for cluster compactness is being followed, using berries per centimeter as a measure of cluster compactness. We have identified several clones with looser clusters than control, non-mutagenized ?Vignoles? vines.